posix: inet_pton for AF_INET
winman: don't memset framebuffer to white before creating a Cairo surface for it
network: TcpManager now complains if you attempt to listen on an already-used port
network: TcpManager now increments the sequence number by 64,000 every half a second, and uses a bitmap to determine which ports are in use instead of a tree with bool pointers.
network: added some TCP todo comments - we don't respect MSS, and our receive window doesn't correlate to anything substantial